Benchmark: TextDecoder vs String.fromCharCode/escape/decodeURIComponent

Script Preparation code:

data = new Uint8Array([
  208, 158, 208, 177, 208, 188, 208, 176, 208, 189, 209,
  131, 209, 130, 209, 139, 208, 185, 32, 47, 32, 84, 104,
  101, 32, 66, 101, 103, 117, 105, 108, 101, 100, 32, 40,
  49, 57, 55, 49, 41, 32, 66, 68, 82, 105, 112
]);

utf8decoder = new TextDecoder('utf-8', { fatal: true })

Tests:

decodeURIComponent/apply
const result = decodeURIComponent(escape(String.fromCharCode.apply(0, data)));
decodeURIComponent/spread
const result = decodeURIComponent(escape(String.fromCharCode(...data)));
TextDecoder
const result = utf8decoder.decode(data)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
decodeURIComponent/apply
decodeURIComponent/spread
TextDecoder

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
decodeURIComponent/apply	1088623.8 Ops/sec
decodeURIComponent/spread	497998.2 Ops/sec
TextDecoder	3719512.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what is being tested.

**Benchmark Definition**

The benchmark measures the performance of three different approaches:

1.  **String.fromCharCode/escape/decodeURIComponent**: This approach uses the `String.fromCharCode` method, followed by the `escape` function, and finally the `decodeURIComponent` function.
2.  **TextDecoder**: This approach uses a `TextDecoder` object with the 'utf-8' encoding scheme to decode the provided binary data.

**Options Compared**

The benchmark compares the performance of two approaches for decoding a URL-encoded string:

*   **String.fromCharCode/escape/decodeURIComponent**: This approach involves three steps: creating an array of characters using `String.fromCharCode`, escaping those characters, and then decoding them with `decodeURIComponent`.
*   **TextDecoder**: This approach uses a single function call to decode the binary data directly.

**Pros and Cons**

Here are some pros and cons for each approach:

*   **String.fromCharCode/escape/decodeURIComponent**:
    *   Pros:
        *   Wide browser support
        *   Can handle non-ASCII characters
    *   Cons:
        *   More steps involved, which can increase overhead
        *   May not be as efficient due to the additional function calls
*   **TextDecoder**:
    *   Pros:
        *   Single-step decoding process reduces overhead
        *   Often more efficient and faster than multiple function calls
    *   Cons:
        *   Less browser support (some older browsers may not have this API)

**Library and Purpose**

The `TextDecoder` object is a part of the Web APIs, introduced in HTML5. It provides a way to decode binary data into a string, using a specified encoding scheme.

In this benchmark, the `TextDecoder` object is used to decode the provided binary data (`data`) directly, which eliminates the need for intermediate steps like escaping and decoding.

**Special JS Features or Syntax**

There are no specific JavaScript features or syntax that are unique to this benchmark. However, it's worth noting that the `escape` function has been deprecated in favor of the `encodeURIComponent` function in modern browsers. The `TextDecoder` object is a relatively new feature, introduced in HTML5.

**Other Alternatives**

If you need to decode binary data into a string, other alternatives include:

*   Using the `Buffer` class (Node.js) or `Uint8Array` (browser-side)
*   Implementing custom decoding logic using bitwise operations and character encoding tables

However, these approaches may not be as efficient or convenient as using the built-in `TextDecoder` object in modern browsers.

Related benchmarks:

TextDecoder vs String.fromCharCode/escape/decodeURIComponent (version: 0)

Comparing performance of: decodeURIComponent/apply vs decodeURIComponent/spread vs TextDecoder

Created: 3 years ago by: Guest

Jump to the latest result

decodeURIComponent/apply

decodeURIComponent/spread

TextDecoder

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):